1. Field of the Invention
The invention relates to an apparatus for charging and discharging a battery device, more particularly to an apparatus for charging and discharging a battery device that can control accurately charging and discharging currents.
2. Description of the Related Art
Lithium batteries are known dc power supplying devices. In the manufacturing process of lithium batteries, it is necessary to repeatedly perform charging and discharging tests for the lithium batteries. Because charging and discharging are conventionally performed using separate circuits, the need to switch between the two circuits during testing results inconvenience and higher costs. In addition, a conventional discharge circuit generally includes a resistor or an electrical load to draw the power from a battery. The electronic load is a power device, such as a BJT or a MOSFET, which has a saturation voltage acting thereon when working in the saturation region. Since the power device is turned off when the battery is discharged to the saturation voltage of the power device, the battery thus cannot be fully discharged by means of the conventional discharge circuit, thereby resulting in an impact on the service life of the battery.